Refrigerating machine



April 15, 1930,- c.,sTEE\\1sTRUa=- 1,755,084

REFRIGERATING MACHINE origial Filed Nov'. 13, 1926 l Ty /6 lsv/4 /z /4 5 A m lz Inventor:

Patented Apr. l5, 193i) CHRISTIAN STEENSTRUP, OF SCHENECTADY, NEW YORK, ASSIGNOR T0 GENERAL ELECTRIC COMPANY, A CORPORATION'OF NEW YORK REFRIGERATING MACHINE Application filed November 13, 1926, Serial No. 148,266. Renewed May 2, 1929.

My invention relates to electric refrigerating machines of the type especially adapted for domestic .use and particularly to the construction and arrangement of the cooling unit of suchmachines. An object of my invention is the provision of an improved cooling unit for such machines, and an arrangement of the same to cool the refrigerator cabinet and facilitate freezing articles therein.

My invention will be better understood from the following description taken in connection with the accompanying drawing, and

.its scope will be pointed out in the appended claims. f

Referring to the drawing, Fig. 1 is a perspective view of a complete electric refrigerator having a cooling unit embodying my invention; Fig. 2 is a perspective view of the cooling unit drawn to a larger scale; Fig. 3

is a longitudinal cross sectionalview of the cooling unit; Figs. 4 and 5 show respectively an ice cube tray and a rack for supporting the same in the cooling unit; Fig. 6 shows a modified form of plate for supporting the ice4 tray;I Fig. 7 shows a modified form of cool,-

ing unit; and Fig. 8 shows a detail.

In Fig. 1 of the drawing I have illustrated an electric refrigerator adapted for domestic use and comprising the refrigerator cabi.- net or box l and the refrigerating machine of which the cooling unit 2 is located within' thev cabinet and the motor driven compressor and condenser 3 are supported on top of the cabinet. .The cooling unit 2 shown more in r' detail in Figs. 2and 3 comprises three cupshaped steel receptacles 5, Gand 7 nested one within another with adjacent walls spaced apart to provide chambers 8 and 9 therebetween, the inside of the receptacle 5 serving as a container for articles to be frozen. The

inner chamber, which is the evaporator of the refrigerating 'machine used to cool the cabinet, contains refrigerant and the outer chamber contains a liquid whereby it func- 4 tions as a heat reservoir. This outer chamber 9 is shown nearly'illed with liquid which preferably is a freezing liquid such as a mixture of glycerine and water or brine, so that r the heat transferred from theiinside ofthe "o receptacle 7, wherein articles to be frozen are enough to readily freeze water in the ice cube tray or other articles placed therein without reducing the temperature in the refrigerator cabinet below that desired t0 keep food or the like above the freezing.telnperature. The evaporator 9 is shown containing liquid refrigerant and passing through. the outer chamber and the outer and intermediate receptacles are the inlet pipe 10 for liquid refrigerant and the outlet pipe 11 for evapo- .rated refrigerant, the pipes being suita connected with the condensing apparatus above. 'lhe mouth .of the outlet pipe 11 is covered by the cap l2 which as shown more clearly in the enlarged detaill view comprising Fig. 8 has large openings near the topand small openings near the bottom. By this construction if a layer of oil collects on the surface of the refrigerent during a shut-down a slug of oil will not be drawn up into the compressor upon starting the machine since' the small openings V14 will limit the flow of oil to the compi-essor while the gas has a free flow through the larger openings 13. This arrangement functions in a similar manner to that disclosed and claimed in my cependiug application, Serial No. 109,960, filed May 1S, 1926 and assigned to the sameassignee as the present application. At their open ends the receptacles have their edges drawn together and welded for example by atomic welding. A I vpreferably make the inner and intermediate receptacles cylindrical in form with their closed. ends rounded whereby de` formation of the receptacles due to pressure is less likely. The outer'receptacle may also be cylindrical if desired but I prefer to make it somewhat rectangular so as to more economically use the space in the box allotted to the cooling' unit. The cooling unit ma convenientlv be sui'iported inl the box by racke'ts' l welded or otherwise secured to the outer 'recepten-le. .'lhe open end of the' cooling unit is closed by the detachable .cover 16 having the handled? and a hook 18at eachside which engages over. a pin 19 on the outer receptacle.

One of the advantages of a refrigerator having articial refrigeration is the ability and convenience with which small ice cubes may be frozen. These cubes are usually made ina pan such as shown for example in Fig. i where a shallow pan 22 preferably of l allV four sides being separated from the cold wall of the evaporator by a layer of air. Inasmuch as air is a relatively 'poor conductor of heat the rate at which heat is withdrawn from the water in the pan is relatively slow with the result that many hours may be required for the freezing of a pan of ice lcubes I have found that the length of time required to freeze a pan of cubes may be very materially lessened by providing a better thermal connection between the pan and the evaporator of the cooling unit whichfacilitates the conduction of heat from the'pan to the cooling unit. This may be accomplished in various ways. In Figs. 2 and 3- I have shown the cooling unit' provided with a barrier 25 eX- tending across the mouth of the inner receptacle and serving as a dam to retain a small amount of freezing liquid 26 therein. This liquid may be plain water which will readily freeze solid or may -be a liquid which will not freeze at the temperatures normally attained in the evaporator. For' supporting the -ice tray I have provided a rack or supporting member 27 comprisinga plate28 of metal or other suitable material of good thermal conductivity from which are punched curved earsl 29 bent down to form supporting legs. The top of the rack whenin position in the cooling unit is a little lower than the top of the barrier so that a suiiicient quantity of freezing liquid may be added to cover the top of the rack. If the liquid used is water and has become frozen when the pan of water to be frozen is inserted, the warmth of the pan of water will melt a part or all of the iceover-4 lying the rack, leaving the tray in good thermal connection throughout its bottom with the evaporator. The Water from -the ice melted/from the top of the rack again freezes around the edges of the tray but is not sufficient to ,interfere with'the subsequent removal of the tray.

Instead of providing the cooling unit with the barrier '25 to r'etain the freezing liquid I may use a removable shallow vessel, such as is illustrated at 30 in'Fig. 6, the bottom of which is curved to fit closely the contour of the inner receptacle. The vessel is shown provided with a number of transverse members 3l the top of which are slightly lower than the walls of the vessel for supporting the ice cube tray. W'hen the vessel is filled with freezing liquid the liquidlevel will be slightly above the tops of the tray supporting members 3l.' Although actual contact between the vessel 30 and the evaporator of the cooling unit may not be uniform over the bottom of the vessel, due to unavoidable variations in the shape of the inner receptcale and of the vessel, it does not materially' affect the rate of heat transfer for in service the entire evaporator becomes coated with a layer of frost so that when the vessel 30 containing water to be frozen is placed in the cooling unit the frost beneath the vessel first melts and then recongeals, t-hus providing agood thermal connection betweenthe vessel and the evaporator of the cooling unit.

In some installations, as for example in hospitals, the chief function of the machine .in the non-freezing liquid will thus have their bottom portions in good thermal connection with the cooling unit. AIt may not leven be necessary to add water to the top of the cooling unit since' sufficient-.moisture may have collected on the evaporator in the form lof frost to provide the necessary water or ice connection between the ice tray and the evaporator.

As has alreadybeen pointed out, the freezn ing liquid contained in the outer AchamberA 9 application, Se-

loo

functionsfas a'heat reservoir, the liquid alternately freezing. when the compressor is running and thawing when the compressor is idle. the-operation ofthe machine being automatically governed in response to the temperature in the refrigerator boX or in the freezing liquid or in part to both. The heat reservoir comprised by the body of freezing i liquid makes the machine less sensitive to sudden and slight changes in temperature andcauses the machine to sta-rt and stop at less frequent intervals than would be the case if Asuch were not provided. The use of freezing liquid further increases the heat capacity of the reservoir since the heat of fusion is available in addition to the heat of the liquid..

In certain instances it may be desirable to provide for 4'more refrigeration within the cooling unit than without it, for example if t-he user is more desirous of being 4able to freeze 'a large number of ice cubes than of maintaining the usual low temperature lin the refrigerator box. In such a case a certain amount of freezing liquid may be withdrawn from chamber 9 so ythat heat is less readily drawn from the box, the air space formerly occupied by freezing liquid serving as a'heat insulator.

What I claim as new and desire to secure by Letters Patent of the United States, is :4

1. In combination with va refrigerator cabinet, a cooling unit therein comprising an inner chamber for receiving articles to be frozen, an outer closed chamber surrounding the inner chamber and adapted to contain a liquid, an intermediate evaporator chamber adapted to contain a refrigerant, and means for circulating the refrigerant through said evaporator chamber;

' 2. In combination l with a refrigerator cabinet, a cooling unit thereinA comprising a plurality of cup-like receptacles nested one Within the other, adjacent-,receptacles being spaced from each other to form\ chambers surrounding theinner receptacle, the ed'gs of the mouths of said receptacles being -4 formed of such size as to closely fit one with-.

in the other, means for securing said edges together, a liquid in one ofsaid chambers, and means for supplying refrigerant to. another of said chambers.

3. In combination with a refrigerator cabinet, a cooling unit therein comprising a plurality ofcup-like receptacles nested one Within the other, adjacent -receptacles being spaced from'e'ach other to form chambers surrounding the inner receptacle, the edges of the mouths of said receptacles being formed of such size as to closely fit one within the other, and means 'for securing said edges together.

, 4. In combination with a refrigerator cabinet, a cooling unit therein comprising a plurality of cup-like receptacles arranged one within the otherand spaced apart to forma spaced from the intermediate receptacle .to

form a heat reservoir chamber, and inlet and outlet pipes passing through the latter charnber and communicating with the refrigerant chamber, said receptacles being welded together at their edge portions.

.6. In combination with arefrigerator cabicooled with its lower said liquid. v

ceptacle adaptedto support an ice tray, said receptacle being provided with means for .retalmng a freezing liquid whereby said tray when in position is in good thermal connection with the evaporator. 7. In combination with a refrigerator cabinet, a coolin yunit therein comprising a receptacle a -apted to receive an article to be y frozen, an evaporator 4surrounding the receptacle, said receptacle vbeing also adapted to retain a body.of freezing liquid therein and means for supporting the article to be portion immersed in 8. In combination with a lrefrigerator `cabinet, a cooling unit therein comprising a cylin- -drical receptacle, an evaporator surrounding said receptacle, sald receptacle having means adapted to support a fiat bottomed ice cube tray therein and for retaining a freezing.'

liquid in contact 'with the tra 49. In combination with a regigerator cabinet, a cooling unit arranged in said cabinet and forming a horizontal cylindrical receptacle for receiving articles to "be frozen, said coolingunit including an' evaporator sur rounding said receptacle and a closed chamber containing a freezing liquid surrounding said evaporator, means` arranged 1n said cylindrical receptacle conforming to the curved bottom thereof and having upper surface vadapted', to conform to the bottom of a Hat freezing tray so as to form a good thermal connection-therewith, and means for circulating a refrigerant through said evaporator.

cabinet, a cooling unit arranged in said cabi-,I net and forming a horizontal cylindrical re- Iceptacle for receiving articles to be' frozen, said cooling unit including an evaporator sur# rounding said receptacle and a closed chamber containing a freezin liquid surrounding said evaporator, means or retaining a .body of liquid in the bottom of said receptacle 1n Contact therewith so as to provide a good thermal "connection with theV freezing tray, and means for circulatlng a refrigerant 'through said evaporator. A

In witness whereof, I have hereunto set my hand this 11th day of November, 1926.

CHRISTIAN STEENSTRUP.

net, a cooling unit therein comprising a ile- 10. In combination with a refrigerate l* ottom of a flat DISCLAIMER l 1,755 084.--0hst'ae b'ieeits'ztrufp, Schenectady, N. Y. `REFRIGERATING MACHINE.

f -atent dated Api-i115, 1930. Disclaimer filed/ April 13, A1931--,--by the'Y assignee,

General Ele ctrc Qmnpany.-

Therefore, enters this disclaimer to claims 2 and 3 of said patent which. are in the i following Words 2. In combination with a refrigerator cabinet, a cooling unit therein comprising a plurality of cup-like receptacles .nested one within the other, adjacent receptacles v being spaced fromeach other to form chambers surroundirg the injer receptacle, the

edges of the mouths of said receptacles being' formedof such size as to closely t one within the other, means for'securing said` ed geslto'gether, a liquid' in one of's'aid chambers, and means for supplying refrigerant to another of'said chambers." y A l Y 3. In combination Witha refri.grex-ato1,l cabinet, a cooling .unit-thereincomprising a plurality of cup-like receptacles nested one within tli'e`otl1er7 adjacent receptacles being spaced from leach other to form chambers surrounding the inner receptacles, the' edges of the mouths of said receptacles being formed 'of such size ast-o closely-fit one within the other, und means for securing said edges together.

[Uf/07212 Gazette A pril $28, 1.031.] 

